Switch mechanism

ABSTRACT

A switching mechanism has at least two terminals partly positioned within a housing and a reciprocal actuator within the housing. A coil spring, under endwise buckling pressure, is mounted between spaced portions of one of the terminals, with movement of the actuator causing the coil spring to pivotally move toward and away from another one of the terminals, thus controlling electrical contact between the two terminals. The coil spring, under endwise pressure by its supporting terminal member, in the normal buckled position, has its axis radially offset from the supporting portions of said terminal member.

United States Patent 1191 Van Benschoten et al.

[ SWITCH MECHANISM [75] Inventors: Peter J. Van Benschoten, Rancho Santa Fe; Jan Albert Kilsdonk, Corona, both of Calif.

[731 Assignees Oak Industries Inc., Crystal Lake, [IL

[ Jan. 28, 1975 962,745 7/1964 Great Britain ZOO/I53 W Primary ExaminerRobert K. Schaefer Assistant ExaminerWilliam J. Smith Attorney, Agent, or Firm-Kinzer, Plyer, Dorn & McEachran [5 7] ABSTRACT [22] Filed: Feb. 14, 1974 [21] AppL No: 442,479 A switching mechanism has at least two terminals partly positioned within a housing and a reciprocal actuator within the housing. A coil spring, under endl Cl /67 DB, 200/159 R, 200/276 wise buckling pressure, is mounted between spaced [5 Clportions of one of the terminals movement of the Fleld of Search R, DB, actuator cau ing the oil pring to pivotauy move toward and away from another one ofthe terminals, References Clled thus controlling electrical contact between the two UNITED STATES PATENTS terminals. The coil spring, under endwise pressure by 2.599437 6/1952 Dickson 200/67 DB its Supporting terminal member, in the normal buckled 3,699,296 10/1972 Harris 200/159 R position, has its axis ia y fset from the Supporting FOREIGN PATENTS OR APPLICATIONS pmons of Said terminal member 685,569 1/1953 Great Britain 200/67 DB 14 Claims, 10 Drawing Figures I 1 1 1 1 I [Z /,;5 1 Z4 1 [4 J 14 A 2! I I I 1 l 12 I 5/ 41 i /z /Z I? I! 74 74 t 675 I! F: I0 ii:

PATENIED JAN28 I975 SHEET 2 OF 4 swrrcu MECHANISM SUMMARY OF THE INVENTION This invention relates to a reciprocal switch mechanism and particularly to such a switch utilizing a buckled coil spring as a portion of the electrical path between terminals.

A primary purpose is an alternate action switch mechanism of the type described in which one of the terminal members mounts, under endwise pressure, a buckled coil spring which pivots toward and away from other terminal members within the switch housing.

Another purpose is a simply constructed reliably operable alternate action switch of the type described.

Another purpose is a switching construction of the type described which may be arranged for either alternate action or momentary action.

Another purpose is a switch construction of the type described in which a coil spring, under endwise pressure from supporting portions of a terminal member, has its axis, in the buckled position, radially offset from the aligned portions of the terminal member.

Other purposes will appear in the ensuing specification, drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated diagrammatically in the following drawings wherein:

FIG. 1 is a perspective view of a switch construction of the type described,

FIG. 2 is an exploded perspective of portions of the switch structure,

FIG. 3 is an exploded perspective of the switch terminals,

FIG. 4 is a section along plane 4-4 of FIG. 1,

FIG. 5 is a section, similar to FIG. 4, but rotated 90 degrees,

FIG. 6 is a partial section, similar to FIG. 4, showing the switching spring in a second position,

FIG. 7 is a perspective view of a modification of one of the switch terminals,

FIG. 8 is a partial section showing a modification of the invention,

FIG. 9 is a partial section, similar to FIG. 8, but showing the switch of FIG. 8 in an operated position, and

FIG. 10 is a perspective view of the slider.

DESCRIPTION OF THE PREFERRED EMBODIMENT Turning first to FIGS. 1, 2 and 3, a switch housing is indicated generally at 10 and may have a somewhat square cross section, although this is not a limiting feature. The housing 10 may have walls 12 and an open top 14. Positioned within the housing 10 is an actuator 16 which is reciprocated by movement of a button 18. The button 18, which may have a transparent top 20, has downwardly-directed fingers 22, each of which have an outwardly-extending locking lug 24. As shown particularly in FIG. 4, the locking lugs 24 move within slots 26 in opposite walls 12 of the housing 10. The lugs 24 and slots 26 cooperate to limit reciprocal movement of the button 18 and the actuator 16.

The actuator l6, may have outwardly-directed lugs 28 on two of its sides, which lugs fit within and are movable within slots 30 in opposite walls 12 of the housing 10. Thus, reciprocal movement of the actuator is controlled by movement of the button 18 and is limited by the cooperation between the lugs 28 and slots 30.

Opposite sides 32 of the actuator 16, which sides contain the lugs 28, have outwardly-opening recesses 34, which receive the fingers 22 of the button 18. This relationship is shown particularly in FIGS. 2 and 4.

Centrally positioned within the hollow actuator 16 is an electric light 36, which extends upwardly into the hollow button 18. Such an electric light is used in many switch constructions, but is not necessary in all. Turning to FIG. 3, a terminal 38 having an outwardly extending terminal lug 40 supports the bottom sphericalshaped contact portion 42 of the light 36, whereas, the side connection for light 36 is formed by a terminal 44 having an outwardly-extending terminal lug 46. Terminal 44 has somewhat curved side wings 48 which are positioned on opposite sides of the light 36. The terminals 38 and 44 may be suitably electrically connected so that the light may operate in conjunction with the switching operation described hereinafter, or the lamp may be operated independently. Both terminals 38 and 44 extend upwardly into the housing 10 and terminal 44 extends inside of the actuator 16, whereas, terminal 38 will support the light 36 from the bottom, as shown particularly in FIG. 5.

The housing 10 may include a base member 50, which may or may not be integral with the housing 10, and which has an outwardly-directed annular flange 52 supporting an actuator return spring 54. The return spring 54 extends upwardly into an annular groove 56 in the bottom of the actuator 16. Thus, the spring 54 provides return movement for both the actuator and the button 18 and is positioned within the housing 10. The annular flange 52 also contains four outwardlyextending fingers 53 which serve to guide the actuator 16 and terminals 38 and 44.

A pair of spaced side terminals 58 and 60, shown in FIG. 3 in perspective, have terminal lug portions 580 and 60a, which extend outwardly from the housing 10 for connection in a conventional manner. Both terminals 58 and 60 have inwardly-extending portions 58b and 60b which extend within the base 50 and are positioned on opposite sides of an intermediate or central terminal 62. Terminal 62 has a terminal lug portion 62a which extends outwardly from the housing 10 and has a central portion 62b which is positioned within the housing and between terminal portions 58b and 60b. The portion 62b of terminal 62 has an opening 62c, shown particularly in FIG. 3.

A contact coil spring 64 is positioned within opening 62c and has its opposite ends pivotally mounted to terminal 62. There is an upwardly extending lug 66 at the lower end of terminal opening 62c, whereas, the upper edge 68 which defines the upper end of opening 62c supports, in a pivotal manner, the upper end of coil 64. A slider member 70 is positioned within the top coil of spring 64 and has an upper flat surface bearing against edge 68 to form the upper pivotal connection of the coil with terminal 62. As shown particularly in FIG. 4, spring 64 is normally under endwise pressure from the spaced terminal supports which pivotally mount the spring, such endwise pressure buckling spring 64 and placing intermediate coils thereof, shown at 72, into electrical and mechanical contact with terminal portion 58b. Thus, terminal 62 and terminal 58 are in electrical contact when the switch is in the position of FIG. 4, the electrical path including the coils of spring 64.

The actuator 16 has downwardly-depending sides 74 and 76 which are positioned for contact with slider 70. At least partly defined by the sides 74 and 76 is an inner hollow area 78.

In operation, and assuming the switch is initially in the position of FIG. 4, wherein there is contact between terminals 62 and 58 through the coils of spring 64, as the actuator 16 moves downwardly due to pressure from button 18, side 76 of the actuator will initially contact the right-hand side of slider 70. Note that in the position of FIG. 4, spring 64 is buckled due to endwise pressure from the supports of terminal 62 and the aligned supports 66 and 68 are radially offset from the axis of spring 64. The initial contact between side 76 and slider 70 will cause the slider 70 to pivot in a clockwise direction about the edge or support 68. The pressure applied to the slider and spring is pivotal and not parallel with the spring axis. Such pressure will cause the spring to move out of contact with terminal portions 58b and 58c and toward a center position within the housing. Continued downward movement of the actuator and button will cause the slider 70 to continue its combined clockwise pivoting and sliding movement about edge 68 to the point where spring 64 will move to the position of FIG. 6 with an abrupt snap action motion. In this position, slider 70 is partially within the space 78 formed by the sides 74 and 76 of the actuator. The aligned portions 66 and 68 supporting the spring are now on the opposite radial side of the axis of spring 64 and coils 72 have made contact with terminal por' tion 60c. The actuator is in its full down position. This condition is shown in FIG. 6.

As the actuator and button are released and begin their return movement to the position of FIG. 4 due to the pressure of spring 54, the coils 72 of spring 64 will wipe along the surface of terminal 600, providing a cleaning action, which is important for good electrical contact. Ultimately, spring 64 will assume the dotted line position of FIG. 4, after the actuator and button have returned to their full release position. Thus, there is now electrical contact between terminals 60 and 62, such contact being effected by the coil spring 64, and the switch is set for the next operating cycle.

The alternate action switch shown first provides electrical contact between terminals 58 and 62, when the spring 64 is in the position of FIG. 4, with an in and out movement of the button 18 causing the actuator 16 to move the spring from the full line position of FIG. 4 to the dotted line position of FIG. 4 in which there is then electrical contact between terminals 60 and 62. The spring provides the electrical path between the terminals with the additional advantage that the spring snaps and wipes the terminals when moving into contact with them, thus providing a clean contact surface and a positive electrical path between terminals. The spring, in its buckled position, caused by endwise pressure from the spring support, has a number of coils in contact with the terminal. The axis of the spring is radially offset from the aligned spring supports when the spring is in the contacting position of FIG. 4, with a satisfactory spacing being approximately half of the spring radius.

FIG. 7 shows a modified form of terminal member which may be used to provide momentary switch action. The terminal member 80 is in most respects the same as the terminal member 60. however, in this case it has a projection 82 extending toward the intermediate or central terminal 62. Thus, if terminal 80 replaced terminal 60, the switch construction would be of the momentary type. Projection 82 would contact spring 64, prior to the time that such contact would be made with terminal 60, and would prevent the slider and spring 64 from reaching the stabilized position shown in dotted lines in FIG. 4. Thus, spring 64 will move into contact with terminal 80, but would not attain a stabilized position in contact with this terminal at such time as the actuator and button are released. Upon button release the spring would move back to the stabilized full line position of FIG. 4.

FIGS. 8 and 9 show portions of a modified form of switch construction particularly useful for high current load. In this case, spaced terminals 84 and 86 are positioned on opposite sides of an intermediate terminal 88. Intermediate terminal 88 can be flexibly moved between the positions of FIGS. 8 and 9 and has a contact portion 90 on the upper end thereof. All of terminals 84, 86 and 88 have suitable conventional contact projections 84a, 88a and b and 86a. A spring support member 92 is fixed to a housing portion 94 and has an opening 96 defining upper and lower spring supports 98 and 100, which may be similar to the spring supports shown in the other forms of the invention.

A coil spring 102 is pivotally mounted to the spring supports in the manner described above and has an upper coil supporting a slider I04. The slider will pivotally move about the spring support I00 in the manner described.

In operation, movement of the actuator will cause the spring 102 to move from the position of FIG. 8. In which there is electrical contact between terminals 84 and 88, to the position of FIG. 9 in which the spring has caused movement of contact portion 90 of terminal 88 so that there is an electrical connection between terminals 86 and 88. There is no electrical path through the spring, as was true in the other forms of the invention. and the total electrical path is through the contacts themselves. A spring of the size shown might not be able to withstand high current loads for extensive periods of time. The switch of FIGS. 1-7 would normally be used in low current applications. The switch of FIGS. 8 and 9 can be arranged for either momentary or alternate action.

Of particular importance in the invention is the fact that the coil spring is normally in a buckled condition due to endwise pressure provided by the spring supports. The spring is positioned in an over center manner or in such a way that the axis of the spring is radially offset from the aligned supports providing the pivot points for the spring. Thus, the spring pivots between two stabilized positions, in the forms of the invention other than in FIG. 7. In one stabilized position, the coils ofthe spring, which form a part of the electrical path. are in contact with one terminal member, whereas, in the other stabilized position other terminals are electrically connected through the coils of the spring. As the spring moves between its stabilized positions it snaps and wipes the electrical contact portions of the terminals, thus providing a clean terminal surface for electrical contact.

In the construction of FIG. 7, the switch is arranged for momentary action in that the projection on the spring is sufficient to prevent the spring from assuming a second stabilized position. Rather, the spring, once the actuator and button are released, moves back to its original and only stabilized position.

In the construction of FIGS. 8 and 9, the spring does not directly form a part of the electrical path, but moves in the manner described to cause a change in the electrical path between different terminal members.

Whereas the preferred form of the invention has been shown and described herein, it should be realized that there may be many modifications, substitutions and alterations thereto.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

I. In a switching mechanism, a housing, at least two terminals partly positioned within said housing, an actuator mounted for reciprocal movement within said housing, return spring means positioned within said housing and normally biasing said actuator outwardly of said housing,

and coil spring means pivotally mounted under endwise buckling pressure between spaced portions of one of said terminals, a slider positioned in one end of said coil spring means and bearing against one of said spaced terminal portions, endwise pressure applied by said spaced terminal portions causing said coil spring means to be flexed into electrical contact with another terminal, said slider being positioned for mechanical contact by said actuator for pivotally moving said coil spring means, about said spaced terminal portions, into and out of electrical contact with said other terminal.

2. The structure of claim 1 further characterized in that said spaced terminals portions are axially aligned.

3. The structure of claim 2 further characterized in that the axis of said flexed coil spring, when in contact with said other terminal, is spaced from said aligned terminal portions.

4. In a switching mechanism, a housing, three spaced terminals, each being at least partly positioned within said housing, an actuator mounted for reciprocal movement within said housing, return spring means positioned within said housing and normally biasing said actuator outwardly of said housing,

coil spring means pivotally mounted under endwise buckling pressure on an intermediate one of said terminals between spaced portions thereof, a slider positioned in one end of said coil spring means and bearing against one of said spaced terminal portions, endwise pressure applied by said spaced terminal portions causing said coil spring means to be flexed into electrical contact with another terminal, said slider being positioned for mechanical contact by said actuator for pivotally moving said spring means, about said spaced terminal portions, from contact with said other terminal, into similar contact with said third terminal.

5. The structure of claim 4 further characterized in that said other terminal and said third terminal are positioned on opposite sides of said one terminal.

6. The structure of claim 4 further characterized in that intermediate turns of said coil spring are in electrical contact with either said other terminal or said third terminal.

7. The structure of claim 4 further characterized in that said spaced terminal portions are aligned within said housing, with the axis of said coil spring being spaced from said aligned terminal portions when said coil spring is in contact with a terminal other than said intermediate terminal.

8. The structure of claim 4 further characterized in that said intermediate terminal has an opening therein, with said spaced terminal portions being formed at opposite ends of said opening.

9. The structure of claim 4 further characterized in that movement of said coil spring from said other terminal to said third terminal causes said slider to be positioned, at least in part, within the confines of said actuator during movement of the slider.

10. The structure of claim 4 further characterized by and including cooperating means on said housing and actuator limiting movement of said actuator.

11. In a switching mechanism, a housing, at least two terminals partly positioned within said housing, an ac tuator mounted for reciprocal movement within said housing, return spring means positioned within said housing and normally biasing said actuator outwardly of said housing,

a spring support member positioned within said housing, a coil spring pivotally mounted to spaced portions of said spring support member with said spaced portions applying endwise collapsing pressure to said coil spring, a slider member mounted in an end coil of said spring and positioned for contact by said actuator,.movement of said actuator into contact with said slider causing said coil spring to pivotally move about its supports and into and out of contact with one of said terminals.

12. The structure of claim 11 further characterized in that the spaced portions of said spring support member are aligned, with the axis of said coil spring being radially offset from said aligned portions.

13. The structure of claim 11 further characterized in that said spring support member functions as an electric terminal.

14. The structure of claim 11 further characterized in that said terminals are positioned on one side of said spring support with movement of said coil spring into contact with a terminal causing said terminal to move into and out of contact with another terminal. 

1. In a switching mechanism, a housing, at least two terminals partly positioned within said housing, an actuator mounted for reciprocal movement within said housing, return spring means positioned within said housing and normally biasing said actuator outwardly of said housing, and coil spring means pivotally mounted under endwise buckling pressure between spaced portions of one of said terminals, a slider positioned in one end of said coil spring means and bearing against one of said spaced terminal portions, endwise pressure applied by said spaced terminal portions causing saiD coil spring means to be flexed into electrical contact with another terminal, said slider being positioned for mechanical contact by said actuator for pivotally moving said coil spring means, about said spaced terminal portions, into and out of electrical contact with said other terminal.
 2. The structure of claim 1 further characterized in that said spaced terminals portions are axially aligned.
 3. The structure of claim 2 further characterized in that the axis of said flexed coil spring, when in contact with said other terminal, is spaced from said aligned terminal portions.
 4. In a switching mechanism, a housing, three spaced terminals, each being at least partly positioned within said housing, an actuator mounted for reciprocal movement within said housing, return spring means positioned within said housing and normally biasing said actuator outwardly of said housing, coil spring means pivotally mounted under endwise buckling pressure on an intermediate one of said terminals between spaced portions thereof, a slider positioned in one end of said coil spring means and bearing against one of said spaced terminal portions, endwise pressure applied by said spaced terminal portions causing said coil spring means to be flexed into electrical contact with another terminal, said slider being positioned for mechanical contact by said actuator for pivotally moving said spring means, about said spaced terminal portions, from contact with said other terminal, into similar contact with said third terminal.
 5. The structure of claim 4 further characterized in that said other terminal and said third terminal are positioned on opposite sides of said one terminal.
 6. The structure of claim 4 further characterized in that intermediate turns of said coil spring are in electrical contact with either said other terminal or said third terminal.
 7. The structure of claim 4 further characterized in that said spaced terminal portions are aligned within said housing, with the axis of said coil spring being spaced from said aligned terminal portions when said coil spring is in contact with a terminal other than said intermediate terminal.
 8. The structure of claim 4 further characterized in that said intermediate terminal has an opening therein, with said spaced terminal portions being formed at opposite ends of said opening.
 9. The structure of claim 4 further characterized in that movement of said coil spring from said other terminal to said third terminal causes said slider to be positioned, at least in part, within the confines of said actuator during movement of the slider.
 10. The structure of claim 4 further characterized by and including cooperating means on said housing and actuator limiting movement of said actuator.
 11. In a switching mechanism, a housing, at least two terminals partly positioned within said housing, an actuator mounted for reciprocal movement within said housing, return spring means positioned within said housing and normally biasing said actuator outwardly of said housing, a spring support member positioned within said housing, a coil spring pivotally mounted to spaced portions of said spring support member with said spaced portions applying endwise collapsing pressure to said coil spring, a slider member mounted in an end coil of said spring and positioned for contact by said actuator, movement of said actuator into contact with said slider causing said coil spring to pivotally move about its supports and into and out of contact with one of said terminals.
 12. The structure of claim 11 further characterized in that the spaced portions of said spring support member are aligned, with the axis of said coil spring being radially offset from said aligned portions.
 13. The structure of claim 11 further characterized in that said spring support member functions as an electric terminal.
 14. The structure of claim 11 further characterized in that said terminals are positioned on one side of said spring suPport with movement of said coil spring into contact with a terminal causing said terminal to move into and out of contact with another terminal. 